Kaposi sarcoma-associated herpesvirus (KSHV) induces heme oxygenase-1 expression and activity in KSHV-infected endothelial cells

Abstract Kaposi sarcoma (KS) is the most common AIDS-associated malignancy and is characterized by angiogenesis and the presence of spindle cells. Kaposi sarcoma-associated herpesvirus (KSHV) is consistently associated with all clinical forms of KS, and in vitro infection of dermal microvascular endothelial cells (DMVECs) with KSHV recapitulates many of the features of KS, including transformation, spindle cell proliferation, and angiogenesis. To study the molecular mechanisms of KSHV pathogenesis, we compared the protein expression profiles of KSHV-infected and uninfected DMVECs. This comparison revealed that heme oxygenase-1 (HO-1), the inducible enzyme responsible for the rate-limiting step in heme catabolism, was up-regulated in infected endothelial cells. Recent evidence suggests that the products of heme catabolism have important roles in endothelial cell biology, including apoptosis and angiogenesis. Here we show that HO-1 mRNA and protein are up-regulated in KSHV-infected cultures. Comparison of oral and cutaneous AIDS-KS tissues with normal tissues revealed that HO-1 mRNA and protein were also up-regulated in vivo. Increased HO-1 enzymatic activity in vitro enhanced proliferation of KSHV-infected DMVECs in the presence of free heme. Treatment with the HO-1 inhibitor chromium mesoporphyrin IX abolished heme-induced proliferation. These data suggest that HO-1 is a potential therapeutic target for KS that warrants further study. (Blood. 2004;103: 3465-3473)

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Atorvastatin and Conditioned Media from Atorvastatin-Treated Human Hematopoietic Stem/Progenitor-Derived Cells Show Proangiogenic Activity In Vitro but Not In Vivo

Mediators of Inflammation ◽

10.1155/2019/1868170 ◽

2019 ◽

Vol 2019 ◽

pp. 1-15 ◽

Cited By ~ 1

Author(s):

Witold N. Nowak ◽

Hevidar Taha ◽

Joanna Markiewicz ◽

Neli Kachamakova-Trojanowska ◽

Jacek Stępniewski ◽

...

Keyword(s):

Endothelial Cells ◽

Heme Oxygenase ◽

Mononuclear Cells ◽

Conditioned Media ◽

Heme Oxygenase 1 ◽

Paracrine Factors ◽

Hematopoietic Stem ◽

Angiogenic Activity

Myeloid angiogenic cells (MAC) derive from hematopoietic stem/progenitor cells (HSPCs) that are mobilized from the bone marrow. They home to sites of neovascularization and contribute to angiogenesis by production of paracrine factors. The number and function of proangiogenic cells are impaired in patients with diabetes or cardiovascular diseases. Both conditions can be accompanied by decreased levels of heme oxygenase-1 (HMOX1), cytoprotective, heme-degrading enzyme. Our study is aimed at investigating whether precursors of myeloid angiogenic cells (PACs) treated with known pharmaceuticals would produce media with better proangiogenic activity in vitro and if such media can be used to stimulate blood vessel growth in vivo. We used G-CSF-mobilized CD34+ HSPCs, FACS-sorted from healthy donor peripheral blood mononuclear cells (PBMCs). Sorted cells were predominantly CD133+. CD34+ cells after six days in culture were stimulated with atorvastatin (AT), acetylsalicylic acid (ASA), sulforaphane (SR), resveratrol (RV), or metformin (Met) for 48 h. Conditioned media from such cells were then used to stimulate human aortic endothelial cells (HAoECs) to enhance tube-like structure formation in a Matrigel assay. The only stimulant that enhanced PAC paracrine angiogenic activity was atorvastatin, which also had ability to stabilize endothelial tubes in vitro. On the other hand, the only one that induced heme oxygenase-1 expression was sulforaphane, a known activator of a HMOX1 inducer—NRF2. None of the stimulants changed significantly the levels of 30 cytokines and growth factors tested with the multiplex test. Then, we used atorvastatin-stimulated cells or conditioned media from them in the Matrigel plug in vivo angiogenic assay. Neither AT alone in control media nor conditioned media nor AT-stimulated cells affected numbers of endothelial cells in the plug or plug’s vascularization. Concluding, high concentrations of atorvastatin stabilize tubes and enhance the paracrine angiogenic activity of human PAC cells in vitro. However, the effect was not observed in vivo. Therefore, the use of conditioned media from atorvastatin-treated PAC is not a promising therapeutic strategy to enhance angiogenesis.

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Heme Oxygenase-1 Deficiency and Oxidative Stress: A Review of 9 Independent Human Cases and Animal Models

International Journal of Molecular Sciences ◽

10.3390/ijms22041514 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1514 ◽

Cited By ~ 1

Author(s):

Akihiro Yachie

Keyword(s):

Oxidative Stress ◽

Animal Models ◽

Heme Oxygenase ◽

Inflammatory Diseases ◽

Cell Types ◽

Pharmacological Intervention ◽

Heme Oxygenase 1 ◽

Inflammatory Reactions

Since Yachie et al. reported the first description of human heme oxygenase (HO)-1 deficiency more than 20 years ago, few additional human cases have been reported in the literature. A detailed analysis of the first human case of HO-1 deficiency revealed that HO-1 is involved in the protection of multiple tissues and organs from oxidative stress and excessive inflammatory reactions, through the release of multiple molecules with anti-oxidative stress and anti-inflammatory functions. HO-1 production is induced in vivo within selected cell types, including renal tubular epithelium, hepatic Kupffer cells, vascular endothelium, and monocytes/macrophages, suggesting that HO-1 plays critical roles in these cells. In vivo and in vitro studies have indicated that impaired HO-1 production results in progressive monocyte dysfunction, unregulated macrophage activation and endothelial cell dysfunction, leading to catastrophic systemic inflammatory response syndrome. Data from reported human cases of HO-1 deficiency and numerous studies using animal models suggest that HO-1 plays critical roles in various clinical settings involving excessive oxidative stress and inflammation. In this regard, therapy to induce HO-1 production by pharmacological intervention represents a promising novel strategy to control inflammatory diseases.

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Abstract 116: Arterial Endothelial Cell Has Stronger Angiogenic Potential Compared To Venous Endothelial Cell Through Up-regulation Of Endogenous FGF2 And FGF5 Expression In 3D Microfluidic System

Circulation Research ◽

10.1161/res.115.suppl_1.116 ◽

2014 ◽

Vol 115 (suppl_1) ◽

Author(s):

Ha-Rim Seo ◽

Hyo Eun Jeong ◽

Hyung Joon Joo ◽

Seung-Cheol Choi ◽

Jong-Ho Kim ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Molecular Mechanisms ◽

Umbilical Vein ◽

Assay System ◽

Vascular Density ◽

Angiogenic Potential ◽

Angiogenesis Assay

Background: Human body contains many kinds of different type of endothelial cells (EC). However, cellular difference of their angiogenic potential has been hardly understood. We compared in vitro angiogenic potential between arterial EC and venous EC and investigated its underlying molecular mechanisms. Method: Used human aortic endothelial cells (HAEC) which was indicated from arterial EC and human umbilical vein endothelial cells (HUVEC) indicated from venous EC. To explore angiogenic potential in detail, we adopted a novel 3D microfluidic angiogenesis assay system, which closely mimic in vivo angiogenesis. Results: In 3D microfluidic angiogenesis assay system, HAEC demonstrated stronger angiogenic potential compared to HUVEC. HAEC maintained its profound angiogenic property under different biophysical conditions. In mRNA microarray sorted on up- regulated or down-regulated genes, HAEC demonstrated significantly higher expression of gastrulation brain homeobox 2 (GBX2), fibroblast grow factor 2 (FGF2), FGF5 and collagen 8a1. Angiogenesis-related protein assay revealed that HAEC has higher secretion of endogenous FGF2 than HUVEC. HAEC has only up-regulated FGF2 and FGF5 in this part of FGF family. Furthermore, FGF5 expression under vascular endothelial growth factor-A (VEGF-A) stimulation was higher in HAEC compared to HUVEC although VEGF-A augmented FGF5 expression in both HAEC and HUVEC. Those data suggested that FGF5 expression in both HAEC and HUVEC is partially dependent to VEGF-A stimulate. HUVEC and HAEC reduced vascular density after FGF2 and FGF5 siRNA treat. Conclusion: HAEC has stronger angiogenic potential than HUVEC through up-regulation of endogenous FGF2 and FGF5 expression

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Heme oxygenase-1 induction by hemin prevents oxidative stress-induced acute cholestasis in the rat

Clinical Science ◽

10.1042/cs20180675 ◽

2019 ◽

Vol 133 (1) ◽

pp. 117-134 ◽

Cited By ~ 7

Author(s):

Pamela L. Martín ◽

Paula Ceccatto ◽

María V. Razori ◽

Daniel E.A. Francés ◽

Sandra M.M. Arriaga ◽

...

Keyword(s):

Oxidative Stress ◽

Heme Oxygenase ◽

Bile Flow ◽

Driving Forces ◽

Membrane Lipids ◽

Ex Vivo ◽

Heme Oxygenase 1 ◽

Canalicular Transporters

Abstract We previously demonstrated in in vitro and ex vivo models that physiological concentrations of unconjugated bilirubin (BR) prevent oxidative stress (OS)-induced hepatocanalicular dysfunction and cholestasis. Here, we aimed to ascertain, in the whole rat, whether a similar cholestatic OS injury can be counteracted by heme oxygenase-1 (HO-1) induction that consequently elevates endogenous BR levels. This was achieved through the administration of hemin, an inducer of HO-1, the rate-limiting step in BR generation. We found that BR peaked between 6 and 8 h after hemin administration. During this time period, HO-1 induction fully prevented the pro-oxidant tert-butylhydroperoxide (tBuOOH)-induced drop in bile flow, and in the biliary excretion of bile salts and glutathione, the two main driving forces of bile flow; this was associated with preservation of the membrane localization of their respective canalicular transporters, bile salt export pump (Bsep) and multidrug resistance-associated protein 2 (Mrp2), which are otherwise endocytosed by OS. HO-1 induction counteracted the oxidation of intracellular proteins and membrane lipids induced by tBuOOH, and fully prevented the increase in the oxidized-to-total glutathione (GSHt) ratio, a sensitive parameter of hepatocellular OS. Compensatory elevations of the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) were also prevented. We conclude that in vivo HO-1 induction protects the liver from acute oxidative injury, thus preventing consequent cholestasis. This reveals an important role for the induction of HO-1 and the consequently elevated levels of BR in preserving biliary secretory function under OS conditions, thus representing a novel therapeutic tool to limit the cholestatic injury that bears an oxidative background.

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HO-1/CO Maintains Intestinal Barrier Integrity through NF-κB/MLCK Pathway in Intestinal HO-1-/- Mice

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/6620873 ◽

2021 ◽

Vol 2021 ◽

pp. 1-19

Author(s):

Zhenling Zhang ◽

Lijing Zhang ◽

Qiuping Zhang ◽

Bojia Liu ◽

Fang Li ◽

...

Keyword(s):

Molecular Mechanisms ◽

Intestinal Barrier ◽

Heme Oxygenase 1 ◽

Zinc Protoporphyrin ◽

Barrier Integrity ◽

Tnf Α ◽

Intestinal Barrier Integrity ◽

Deficient Mice

Background. Intestinal barrier injury is an important contributor to many diseases. We previously found that heme oxygenase-1 (HO-1) and carbon monoxide (CO) protect the intestinal barrier. This study is aimed at elucidating the molecular mechanisms of HO-1/CO in barrier loss. Materials and Methods. We induced gut leakiness by injecting carbon tetrachloride (CCl4) to wildtype or intestinal HO-1-deficient mice. In addition, we administrated tumor necrosis factor-α (TNF-α) to cells with gain- or loss-of-HO-1 function. The effects of HO-1/CO maintaining intestinal barrier integrity were investigated in vivo and in vitro. Results. Cobalt protoporphyrin and CO-releasing molecule-2 alleviated colonic mucosal injury and TNF-α levels; upregulated tight junction (TJ) expression; and inhibited epithelial IκB-α degradation and phosphorylation, NF-κB p65 phosphorylation, long MLCK expression, and MLC-2 phosphorylation after administration of CCl4. Zinc protoporphyrin completely reversed these effects. These findings were further confirmed in vitro, using Caco-2 cells with gain- or loss-of-HO-1-function after TNF-α. Pretreated with JSH-23 (NF-κB inhibitor) or ML-7 (long MLCK inhibitor), HO-1 overexpression prevented TNF-α-induced TJ disruption, while HO-1 shRNA promoted TJ damage even in the presence of JSH-23 or ML-7, thus suggesting that HO-1 dependently protected intestinal barrier via the NF-κB p65/MLCK/p-MLC-2 pathway. Intestinal HO-1-deficient mice further demonstrated the effects of HO-1 in maintaining intestinal barrier integrity and its relative mechanisms. Alleviated hepatic fibrogenesis and serum ALT levels finally confirmed the clinical significance of HO-1/CO repairing barrier loss in liver injury. Conclusion. HO-1/CO maintains intestinal barrier integrity through the NF-κB/MLCK pathway. Therefore, the intestinal HO-1/CO-NF-κB/MLCK system is a potential therapeutic target for diseases with a leaky gut.

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Hydroxychloroquine Synergizes With The PI3K Inhibitor BKM120 to Exhibit Antitumor Efficacy Independent of Autophagy

10.21203/rs.3.rs-691658/v1 ◽

2021 ◽

Author(s):

Xin Peng ◽

Shaolu Zhang ◽

Wenhui Jiao ◽

Zhenxing Zhong ◽

Yuqi Yang ◽

...

Keyword(s):

Tumor Cells ◽

Cell Biology ◽

Molecular Mechanisms ◽

Critical Role ◽

Single Agent ◽

Antitumor Efficacy ◽

Antitumor Effects ◽

Autophagy Inhibitor

Abstract Background: The critical role of phosphoinositide 3-kinase (PI3K) activation in tumor cell biology has prompted massive efforts to develop PI3K inhibitors (PI3Kis) for cancer therapy. However, recent results from clinical trials have shown only a modest therapeutic efficacy of single-agent PI3Kis in solid tumors. Targeting autophagy has controversial context-dependent effects in cancer treatment. As a FDA-approved lysosomotropic agent, hydroxychloroquine (HCQ) has been well tested as an autophagy inhibitor in preclinical models. Here, we elucidated the novel mechanism of HCQ alone or in combination with PI3Ki BKM120 in the treatment of cancer.Methods: The antitumor effects of HCQ and BKM120 on three different types of tumor cells were assessed by in vitro PrestoBlue assay, colony formation assay and in vivo zebrafish and nude mouse xenograft models. The involved molecular mechanisms were investigated by MDC staining, LC3 puncta formation assay, immunofluorescent assay, flow cytometric analysis of apoptosis and ROS, qRT-PCR, Western blot, comet assay, homologous recombination (HR) assay and immunohistochemical staining. Results: HCQ significantly sensitized cancer cells to BKM120 in vitro and in vivo. Interestingly, the sensitization mediated by HCQ could not be phenocopied by treatment with other autophagy inhibitors (Spautin-1, 3-MA and bafilomycin A1) or knockdown of the essential autophagy genes Atg5/Atg7, suggesting that the sensitizing effect might be mediated independent of autophagy status. Mechanistically, HCQ induced ROS production and activated the transcription factor NRF2. In contrast, BKM120 prevented the elimination of ROS by inactivation of NRF2, leading to accumulation of DNA damage. In addition, HCQ activated ATM to enhance HR repair, a high-fidelity repair for DNA double-strand breaks (DSBs) in cells, while BKM120 inhibited HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51. Conclusions: Our study revealed that HCQ and BKM120 synergistically increased DSBs in tumor cells and therefore augmented apoptosis, resulting in enhanced antitumor efficacy. Our findings provide a new insight into how HCQ exhibits antitumor efficacy and synergizes with PI3Ki BKM120, and warn that one should consider the “off target” effects of HCQ when used as autophagy inhibitor in the clinical treatment of cancer.

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DEPTOR Deficiency-Mediated mTORc1 Hyperactivation in Vascular Endothelial Cells Promotes Angiogenesis

Cellular Physiology and Biochemistry ◽

10.1159/000488619 ◽

2018 ◽

Vol 46 (2) ◽

pp. 520-531 ◽

Cited By ~ 7

Author(s):

Yan Ding ◽

Lanlan Shan ◽

Wenqing Nai ◽

Xiaojun Lin ◽

Ling Zhou ◽

...

Keyword(s):

Endothelial Cells ◽

Signaling Pathway ◽

Molecular Mechanisms ◽

Gene Knockout ◽

Umbilical Vein ◽

Vascular Endothelial Cell ◽

Tube Formation ◽

Vascular Endothelial

Background/Aims: The mechanistic target of rapamycin (mTOR) signaling pathway is essential for angiogenesis and embryonic development. DEP domain-containing mTOR-interacting protein (DEPTOR) is an mTOR binding protein that functions to inhibit the mTOR pathway In vitro experiments suggest that DEPTOR is crucial for vascular endothelial cell (EC) activation and angiogenic responses. However, knowledge of the effects of DEPTOR on angiogenesis in vivo is limited. This study aimed to determine the role of DEPTOR in tissue angiogenesis and to elucidate the molecular mechanisms. Methods: Cre/loxP conditional gene knockout strategy was used to delete the Deptor gene in mouse vascular ECs. The expression or distribution of cluster of differentiation 31 (CD31), vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1 alpha (HIF-1α) were detected by immunohistochemical staining or western blot. Tube formation assay was used to measure angiogenesis in vitro. Results: Deptor knockdown led to increased expression of CD31, VEGF and HIF-1α in heart, liver, kidney and aorta. After treatment with rapamycin, their expression was significantly down regulated. In vitro, human umbilical vein endothelial cells (HUVECs) were transfected with DEPTOR-specific small interfering RNA (siRNA), which resulted in a significant increase in endothelial tube formation and migration rates. In contrast, DEPTOR overexpression markedly reduced the expression of CD31, VEGF and HIF-1α. Conclusions: Our findings demonstrated that deletion of the Deptor gene in vascular ECs resulted in upregulated expression of CD31 and HIF-1α, and further stimulated the expression of VEGF which promoted angiogenesis, indicating that disruption of normal angiogenic pathways may occur through hyperactivation of the mTORC1/HIF-1α/VEGF signaling pathway.

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Alleviation of Cartilage Destruction by Sinapic Acid in Experimental Osteoarthritis

BioMed Research International ◽

10.1155/2019/5689613 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Dawei Cai ◽

Thomas W. Huff ◽

Jun Liu ◽

Tangbo Yuan ◽

Zijian Wei ◽

...

Keyword(s):

Heme Oxygenase ◽

Nuclear Translocation ◽

Sinapic Acid ◽

Heme Oxygenase 1 ◽

Related Factor ◽

Transactivation Activity ◽

Nrf2 Signaling Pathway ◽

Primary Mouse

Sinapic acid (SA) modulates the nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway in chondrocytes. In order to test the hypothesis that SA is protective against the development of osteoarthritis (OA), primary mouse chondrocytes were treated in vitro with SA and the promoter transactivation activity of heme oxygenase 1 (HO-1), nuclear translocation of Nrf2, and protein expression of HO-1 were assayed. To test the hypothesis in vivo, a destabilization of the medial meniscus (DMM) model was used to induce OA in the knees of mice and SA was delivered orally to the experimental group. The chondrocytes were harvested for further analysis. The expression of HO-1 was similarly upregulated in cartilage from both the experimental mice and human chondrocytes from osteoarthritic knees. SA was found to enhance the promoter transactivation activity of heme oxygenase 1 (HO-1) and increase the expression of Nrf2 and HO-1 in primary chondrocytes. Histopathologic scores showed that the damage induced by the DMM model was significantly lower in the SA treatment group. The addition of a HO-1 inhibitor with SA did not show additional benefit over SA alone in terms of cartilage degradation or histopathologic scores. The expression of TNF-α, IL-1β, IL-6, MMP-1, MMP-3, MMP-13, ADAMTS4, and ADAMTS5 was significantly reduced both in vitro and in vivo by the presence of SA. Protein expressions of HO-1 and Nrf2 were substantially increased in knee cartilage of mice that received oral SA. Our results suggest that SA should be further explored as a preventative treatment for OA.

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Heme Oxygenase-1, a Key Enzyme for the Cytoprotective Actions of Halophenols by Upregulating Nrf2 Expression via Activating Erk1/2 and PI3K/Akt in EA.hy926 Cells

Oxidative Medicine and Cellular Longevity ◽

10.1155/2017/7028478 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 6

Author(s):

Xiu E. Feng ◽

Tai Gang Liang ◽

Jie Gao ◽

De Peng Kong ◽

Rui Ge ◽

...

Keyword(s):

Heme Oxygenase ◽

Antioxidant Activities ◽

Heme Oxygenase 1 ◽

Protective Effects ◽

Key Enzyme ◽

Ea.Hy926 Cells ◽

Anti Inflammatory ◽

Mechanistic Basis

Increasing evidence has demonstrated that heme oxygenase-1 (HO-1) is a key enzyme triggered by cellular stress, exhibiting cytoprotective, antioxidant, and anti-inflammatory abilities. Previously, we prepared a series of novel active halophenols possessing strong antioxidant activities in vitro and in vivo. In the present study, we demonstrated that these halophenols exhibited significant protective effects against H2O2-induced injury in EA.hy926 cells by inhibition of apoptosis and ROS and TNF-αproduction, as well as induction of the upregulation of HO-1, the magnitude of which correlated with their cytoprotective actions. Further experiments which aimed to determine the mechanistic basis of these actions indicated that the halophenols induced the activation of Nrf2, Erk1/2, and PI3K/Akt without obvious effects on the phosphorylation of p38, JNK, or the expression of PKC-δ. This was validated with the use of PD98059 and Wortmannin, specific inhibitors of Erk1/2 and PI3K, respectively. Overall, our study is the first to demonstrate that the cytoprotective actions of halophenols involve their antiapoptotic, antioxidant, and anti-inflammatory abilities, which are mediated by the upregulation of Nrf2-dependent HO-1 expression and reductions in ROS and TNF-αgeneration via the activation of Erk1/2 and PI3K/Akt in EA.hy926 cells. HO-1 may thus be an important potential target for further research into the cytoprotective actions of halophenols.

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